Issue when calling fnSetFilteringDelay() on multiple DataTables

I lost an entire afternoon on what turned out to be a really stupid issue. I've been unable to find anyone with a similar issue so I figured I'd post it here just in case anyone else has a similar problem:

I have a page with two datatables. Both have server side processing, and both have links within them that open up within a colorbox. The colorbox content allows the users to edit records, so when they close the colorbox I have the datatable refresh.

Here's a portion of the dataTable initialization, which has worked well:

                "fnServerParams": function (aoData) { aoData.push({ "name": "forcerefresh", "value": bForceRefresh }); },
                "fnDrawCallback": function () {
                    $("#tblOneID a.boxit").colorbox({
                        width: "80%",
                        height: "90%",
                        iframe: true,
                        onClosed: function () {
                            bForceRefresh = true;
                            jQuery('#tblSubmitted').dataTable().fnDraw();
                            bForceRefresh = false;
                        }
                    });
                }

(Note: the bForceRefresh stuff is a parameter passed back to the server to tell my code to rebuild some objects instead of relying on cached objects. Not really relevant to this issue.)

Here's where I ran into major problems: Although each table has its own ID, they share a class name. I added FilteringDelay to both with this line of code:

jQuery('.tableclass').dataTable().fnSetFilteringDelay();

This worked great...but I found that whenever the colorbox was closed, I was getting a JS error:

Uncaught TypeError: Cannot read property 'oFeatures' of null

This is what killed my afternoon.

Long story short, I replaced the line of code above with this:

jQuery('#tblOneID').dataTable().fnSetFilteringDelay();
jQuery('#tblTwoID').dataTable().fnSetFilteringDelay();                        

This resolved the problem. I hope this helps someone else.